The pelvis is actually a very strong bony girdle. I don't believe a normal sized person can fracture the pubic bone from a kick, unless you are wearing steel boots or something like that. Your toes, or the metatarsal bones in the foot would likely break before any damage was done to the pubic bone.
That said, the urethra could and will get bruised, but unless using huge force, no permanent damage should ensue.